You. Yes you. Don't sit around looking so smug. You're not perfect—and now, scientists have the evidence to back up that very claim.

Everyone knows that DNA occasionally has flaws in it: some are harmless because of the high level of redundancy in those life-defining chemical chains, while others give rise to genetic conditions that can seriously affect peoples' lives. Until now, though, it's been unclear just how imperfect the average human is. Chris Tyler-Smith, from Cambridge University, explained to NPR:

"It's such an interesting question that people had been trying to make estimates from indirect approaches for a long time. There were estimates that ranged from just a handful up to 100 or more serious disease-associated mutations."

But Tyler-Smith is part of the 1,000 Genomes project, so he was able to answer the question properly. He's helped analyze the genomes of 179 people—spread all over the world—to work out the answer. The results are published in The American Journal of Human Genetics.

Turns out, the average person has around 400 defects in their genes—including at least one or two that are associated with disease. That's way, way more than previously expected. In fact, 1-in-10 people have genetic mutations that should cause a disease, but weirdly none of the people who were analyzed in the study were sick. There's an answer to that, though. Tyler-Smith explained to NPR:

"It's a bit surprising that people should be walking around apparently healthy yet we're seeing known disease-causing mutations in their genomes. But the answer was that these tended to be for mild and very often late-onset conditions. Things like heart disease, an increased risk of developing cancer."